John Wyndham came up with an original alien invasion in his novel The Midwich Cuckoos (1957); Wolf Rilla's film, from a script by the American Stirling Silliphant (who uses a few Yank expressions that should have been changed - 'general store' for 'village shop'), is a low-key dramatisation and all the better for it.

The first half covers the Midwich blackout, so the business with the children - which takes place over years of plot-time - is sometimes a little rushed. There are a lot of secondary characters to cope with and the splendid Barbara Shelley (most caring of the mothers) gets pushed into the background so her scientist husband (George Sanders) can shoulder dramatic weight.

The sleeping village set-up is classic Quatermass stuff - a tractor grinding around in a circle, an iron burning a hole in a dress, a record stuck in a groove, a cow collapsed in a field. Everyone wakes up in convincing embarrassment, which gets odder as the pregnancies are announced, delivering the sort of emotions American s-f films, pitched at kiddies, didn't do in the 1960s: the awkward joy of the Zellabys at an unexpected event, the meek terror of the teenage virgin confessing to a doctor, the mute rage of the sailor home after a year abroad to find his wife knocked up, the quiet solidarity of a pregnant mother and daughter who visit the clinic at the same time.

Once the kids are born, it becomes a monster movie in which the threat is a malign higher intelligence with no moral grounding. What works is the shape the threat comes in: the Midwich Children are the creepiest ever seen on film, with identical blonde wigs (an unsettling effect is achieved by casting real-life brunette kids whose colouring is subtly wrong for their hair) and staring eyes (in some prints, a glowing effect was added). The polite spokesman for the group mind is played by Martin Stephens (also notable as Miles in The Innocents (d. Jack Clayton, 1961)) but dubbed by a grown woman. Rilla hints at the children's human side (they all solve a puzzle box to get chocolates) as well as a malevolence that is scary from an alien but might be even scarier from a human kid (Stephens' flicker of an almost-smile after forcing a motorist to kill himself is one of the nastiest shots in British cinema).

In spread-the-unease form, it ends with one of the first it-may-not-be-over endings (later a genre cliché): the glowing eyes, superimposed over the fire, zap off into the skies, suggesting that killing the kids' bodies may not have wiped out their disembodied intelligence.